A questionably-manufactured metal chess set
It started when Joyce was going to buy a chess set from Amazon. There's nothing wrong with the chess sets there, but they're made of plastic and aren't very interesting. So I offered to make one out of metal instead. Here's what I ended up with:
Almost everything involved was the combination of a vise, a cheap angle grinder, and a cordless drill. The only interesting part of the setup is the way the angle grinder is mounted, which makes it possible to make guided cuts using the table saw sled.
Machining the bases
I decided that pawns would be 1.5" tall, pieces 2", and king/queen 2.5". Pawns were made from 3/8" bar and everything else from 1/2", and the base weights were hex nuts that I turned using an angle grinder as a makeshift lathe. Here's that process, starting with the hex nuts jammed onto the rod:
And the turning process:
The first time I tried this I started grinding on the near side and let the bar rest on the newly-turned outlines. This didn't work out very well, though; it amplified any off-centeredness from each piece to the next. I ended up using a half washer against the bar threads to get better results:
Then I cut each piece off of the rod using a cutoff wheel on the angle grinder. It helped a lot to have the grinder mounted in a fixed position and to rely on the table saw sled for linear motion.
Here are the separated piece bases:
Making the pieces
Most of the definition for each piece is just the placement of additional hex nuts onto the threaded base. Visually here's the layout:
Bishop Knight Rook |==========| <----> <- threads <----> |==<---->==| <----> <----> |==<---->==| |==<---->==| <----> |==<---->==| |==<---->==| <----> |==<---->==| |==<---->==| <- hex nuts <----> |==<---->==| |==<---->==| <----> <----> |==<---->==| <----> <----> |==<---->==| <----> <----> |------| |------| |------| |------| |------| |------| |------| <- turned base |------| |------| |------| |------| |------| |------| |------| |------|
Here's each piece before and after detailing:
King and queen
These were interesting to make because there's a ball bearing press-fit onto the bottom of each one. I didn't take any pictures of these, but the basic process went like this:
- Chuck a 2.5" rod into the drill
- Spin it and use the angle grinder to machine about 1/4" on the end, until it's close to the bearing size
- Use the vise to press-fit the bearing onto the end
The queens also have some washers jammed between two hex nuts. Originally the washers were much larger (and not well centered), but I turned them against the angle grinder using the drill. This wasn't easy and I ended up clamping the drill to the table saw sled to stabilize it.
Bishops and rooks
The rooks were cut freehand. The results were a little rough, but it saved the trouble of positioning a vise to use the sled.
Cutting the diagonal slot for the bishops was straightforward, although I carelessly decapitated one of my prototypes -- after that I made sure to check the depth for each one. (There were a number of casualties that met similarly undignified ends.)
The knights are cool because they have a half-washer press-fit into a vertical slot in the rod. It took me a bit to figure out how to make these, but here's the process I ended up with.
First I needed to cut a straight slot into each base, which was easy enough:
The washers are thicker than the cutoff wheel, so I had to bench grind them on one end to make a wedge.
Then I could use the vise to force them into the slots:
Once they're fully in the slots, there's a little friction holding them down but not much. The rod is also visibly bent outwards.
At this point I put it back in the vise to clamp the washer securely.
Now we've got this:
Everything else is freehand angle grinder cuts through the washer.
Black and white pieces
I didn't want to paint the pieces, so I used a torch to heat the metal instead. In hindsight this wasn't a great way to do it; a lot of the black pieces came out unevenly heated as a result. A better strategy probably would have been to cook the pieces in the oven to get a consistent and precisely-controlled temperature.
The contrast wasn't quite as good as I had hoped it would be, but in reasonable lighting you can easily tell the colors apart.
Clocking in at just under 5lbs for the whole set, of which over one pound is just pawns: